Why can't view PDFs in Chrome after installing ADE?

A coworker of mine installed Adobe Digital Editions on her PC as required to read E-books on the American Medical Association's website.  She uses Google Chrome as her default web browser, which she used to download the install file for ADE.  She installed ADE, did not register it as she wanted to view the e-books solely on her one PC.  However, now when she opens up normal PDFs while browsing with Chrome, the PDFs attempt to load (for several minutes), but never display.  When she goes to use Firefox to view the PDFs within the browser, there is no problem at all.  Did the installation of ADE somehow mess with any plugins within Chrome to where she can't view PDFs within Chrome?  Any help would be great.  Please respond